Is The Scarlet Letter in the public domain?

I know it's really old, and I get all of that, so I don't really need "Yeah it was written in 1850" or anything like that. I don't even want the current rules about public domain. Any concrete evidence that says this novel specifically is in the public domain is what I need--the story, obviously, not a specific version by a publisher or adapted play, etc.

For a source and good answer 10 points for sure, thanks!